Modular manifold brake hose end fitting

ABSTRACT

A high pressure manifold brake hose end fitting used in a brake system to reduce the number of wet fittings required in the brake system. The manifold brake hose end fitting has a crimped sleeve connection to a reinforced rubber brake hose on one end, a first receptacle for a hydraulic fitting on the opposite end and a second receptacle formed in the side of the fitting between the one end and the opposite end. A conduit is provided for hydraulic fluid flow through the fitting and in one embodiment, the conduit is preferably eccentrically located away from the side of the fitting including said second receptacle. An end fitting providing three or more receptacles in a single fitting that may be part of one or more fluid systems is disclosed. A brake system and a method of installing brake fluid conduits are also disclosed which use the end fitting to reduce the number of wet fittings in a brake system and reduce the number of steps required to install a brake fluid conduit on a vehicle.

This is a division of application Ser. No. 866,256 filed on May 23, 1986now U.S. Pat. No. 4,772,051.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to end fittings for brake hoses and animproved hydraulic brake system utilizing manifold brake hose endfittings.

II. Brief Description of the Background Art

Hydraulic brake systems have long been used to provide braking forautomotive vehicles. In vehicle braking systems, a hydraulic systemfunctions as a control link being the operator's brake pedal, the mastercylinder and the wheel braking mechanism. Braking mechanisms mayinclude, for example, calipers for disc brakes or brake shoes for drumbrakes.

The present invention is primarily concerned with the hydraulic systemfrom the master cylinder to the brake mechanism located on the vehiclewheels. Hydraulic fluid transmits operator foot pressure from the mastercylinder to the brake mechanism through steel tubing and reinforcedrubber hose. The reinforced rubber hose is used to interconnect therigid steel tubing segments of the braking system which are mounted tothe chassis and either additional rigid steel tubing or brake mechanismparts which are mounted either to the axle or to the wheel hub.

Referring now to FIG. 4, a prior art braking system is shownschematically wherein a trunk line leads from the master cylinder to apoint on the chassis adjacent the axle where it is connected to aflexible reinforced rubber hose which is connected on its other end to aseparate tee fitting. The tee fitting is connected to two sections ofrigid hydraulic tubing which extend in opposite directions along theaxle toward each of the vehicle wheels. Each axle-mounted length ofsteel tubing is connected to the brake mechanism by means of anadditional flexible, reinforced rubber hose.

An important consideration in the design of brake systems is theminimization of the number of "wet fittings". A "wet fitting" is athreaded connection between serially connected elements of the hydraulicbrake line system. In vehicle assembly operations, wet fittings requirecareful assembly and subsequent testing to ensure the integrity of thehydraulic brake system. The great majority of leaks in hydraulic brakesystems occur at wet fittings. Therefore, it is an object when designinghydraulic brake systems to minimize the number of wet fittings. Flexiblereinforced rubber hoses, referred to herein as brake hoses, havegenerally been used as links in a hydraulic brake system where there isrelative movement between two parts, such as between the frame and anaxle, between the frame and a wheel hub, or between the axle and a brakemechanism attached to a wheel. Brake hoses generally have fittings onboth ends that are attached to the hose by a crimped connection which iscapable of withstanding pressures up to 3,000 psi.

It is an objective of the present invention to provide an improved brakehose end fitting which functions as a manifold wherein a plurality ofhydraulic fitting connections may be made in a single fitting.

Another object of the present invention is the provision of a brake hoseend fitting of minimum outer diameter and incorporating one or morereceptacles for receiving end fittings of tubing or other lengths ofbrake hose.

A further object of the present invention is to provide a brakehydraulic system wherein the minimum number of wet fittings are requiredthereby reducing manufacturing costs and improving reliability.

An additional objective of the present invention is to provide a methodof assembling a brake hydraulic system wherein a manifold brake hose endfitting is used to interconnect a wheel brake hose to the chassis brakeline and to a second portion of the hydraulic brake system which routeshydraulic fluid pressure to a second wheel.

SUMMARY OF THE INVENTION

In accordance with the invention, a manifold brake hose end fittingformed as a solid one-piece body is provided which interconnects atleast three segments of a hyraulic brake system. The end fittingcomprises a body with an inlet port on one end that opens into aninternal conduit formed inside the body. Two female connectors areformed on other surfaces of the body which open into the internalconduit. The female connectors are cylindrical openings having internalthreads formed on its cylindrical sides and an end face at the inner endhaving a convex conical nipple centrally located in the inner end facewhich defines an opening for fluid communication with the internalconduit. One of the female connectors is preferably formed in a firstlateral side of the body. The internal conduit extending through thebody is closer to the lateral side opposite the first lateral side. Theeccentric location of the internal conduit relative to the first side isintended to minimize the size of the fitting while accommodating a maleconnector wherein the base face of the female connector does not openinto the conduit.

In accordance with another aspect of the invention, the manifold brakehose end fitting comprises a body having an inlet port on one end whichopens into an internal conduit formed through the body. The body of theend fitting has a plurality of wrench flats on its exterior. At leasttwo female connectors are formed in the body with one female connectorpreferably being located on the opposite end from the inlet port and asecond female connector being formed in the body to intersect theconduit between the inlet port and first female connector, the secondfemale connector being substantially confined to one of said wrenchflats.

A brake system made in accordance with the present invention comprises abrake actuator, such as a brake pedal, which is mechanically connectedto a master cylinder which contains hydraulic fluid for transmittinghydraulic pressure to the brakes of a vehicle. The hyraulic fluid isdistributed through a system comprising a series of steel and reinforcedrubber tubes which conduct hydraulic pressure to either the rear orfront wheels. The brake system of the present invention is furthercharacterized by the provision of an end fitting at the end of a firstbrake hose which is connected to the front or rear trunk line whichincludes a second female connector for interconnection with a secondbrake hose or tube in a manifold relationship. If the secondinterconnection is a steel brake tube, it may be an axle brake tube linewhich extends from the connection to the end of the axle to be connectedwith a brake hose or a brake mechanism.

In accordance with the method of the present invention, a hydraulicbrake fluid conduit system may be attached to a vehicle by firstattaching a trunk line to a master cylinder on one end and securing theother end of the trunk line to the chassis adjacent the front or rearaxle. The second end of the trunk line is provided with a male connectorwhich is adapted to be received in one of two female connectors formedin a brake hose end fitting of a brake hose which is directly connectedto a brake mechanism of a wheel. The end fitting further includes asecond female connector to which a second brake hose or brake tube lineis attached. The method of the present invention may alternativelycomprise securing an axle brake tube line to the axle and in turnconnecting a brake hose to the other end of the tube and the other brakemechanism.

Other objects and advantages of the invention will become apparent uponreading the following detailed description and upon reference to thedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a manifold brake hose end fittingattached to a brake hose and a hydraulic brake hose fitting.

FIG. 2 is a cross-sectional view of the manifold brake hose end fittingtaken along the line 2--2 in FIG. 1.

FIG. 3 is a side elevational view of a four port manifold brake hose endfitting with the four ports and the internal conduit interconnecting thefour ports shown in phantom lines.

FIG. 4 is a schematic representation of a prior art front brakehydraulic system.

FIG. 5 is a schematic representation of a front end hydraulic brakesystem implementing the present invention.

FIG. 6 is a fragmentary perspective view partially exploded of a priorart rear axle hydraulic system.

FIG. 7 is a perspective partially exploded fragmentary view of a rearaxle and brake hydraulic system.

FIG. 8 is an elevational view of a manifold brake hose end fittingshowing a primary hydraulic fluid conduit and distribution femaleconnectors and a parallel fluid circuit comprising a separate conduitand female connectors for a parallel hydraulic or pneumatic circuit.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, in particular FIGS. 1 and 2, a solid,one-piece manifold brake hose end fitting 20 is shown attached to abrake hose 21. The reinforced elastomeric brake hose 21 is attached tothe end fitting 20 by a crimped fitting 23 wherein an integrally formedsleeve 25 is collapsed to compress the reinforced elastomeric tubingbetween the sleeve 25 and a tubular extension 26 centrally locatedwithin the sleeve 25. The tubular extension 26 is received within thebrake hose 21 prior to collapsing the sleeve 25. The tubular extension26 aligns the brake hose 21 with an internal conduit 28 formed in thebody of the end fitting 20.

The internal conduit 28 is contiguous with the tubular extension 26 sothat hydraulic fluid may flow within the brake hose 21 through thetubular extension 26 and into the internal conduit 28. The internalconduit 28 extends through the end fitting 20 to two or more ports 30.The plurality of ports 30 impart to the end fitting 20 its manifoldcapability wherein fluid pressure from a single source may bedistributed to a plurality of hydraulically operable devices.

The ports 30 of the internal conduit 28 open into female connectors 32,which are preferably high pressure hydraulic fittings. High pressure isdefined as being more than 500 psi. The female connectors 32 comprise athreaded bore 33 which extends into the end fitting 20 a predetermineddistance where it terminates in an end face 34 which is disposedsubstantially perpendicular to the threaded bore 33 and includes acentrally located convex conical nipple 35 that surrounds the port 30and extends outwardly from the base face 34.

Male connectors 37, preferably of the high pressure hydraulic fittingtype, are adapted to be received within the female connectors 32. Themale connectors 37 have an externally threaded tubular portion 38 whichis received within the threaded bore 33. The threaded tubular portion 38terminates in a concave conical surface 39 disposed about a central bore40.

The female connectors 32 and male connectors 37 are designed to form aseal when connected together. The connection between the femaleconnectors 32 and male connectors 37 is referred to as a "wet fitting"since the two respective parts are normally not connected until assemblyof the system. In vehicle assembly operations the wet fittings of thebrake hydraulic system are generally assembled on-line in the assemblyoperation and require considerable care in assembly and subsequenttesting to assure the integrity of the brake system.

In a preferred embodiment of the present invention, wrench flats 41 areformed on the exterior sides of the end fitting 20 which permit a wrenchto be applied to the fitting during assembly and service operations. Inthe preferred embodiment, as shown in FIG. 1, at least one of the femaleconnectors 32 extends through only one of the wrench flats 41 so thatthe male connector 37 may be connected to one of the wrench flats 41.

It has been found that to minimize the required diameter of an endfitting 20, the internal conduit 28 should be eccentrically locatedcloser to the side opposite the wrench flat in which the femaleconnector 32 is formed, thereby preventing the base face 34 from openinginto the conduit 28. While it is recognized that the use of a largerdiameter end fitting 20 may obviate the need for an eccentricallylocated conduit 28, for weight reduction it is preferred to use thesmallest possible end fitting 20 for each application.

Referring now to FIG. 3, an end fitting 20 having four ports 30connected by the internal conduit 28 is illustrated. The internalconduit 28 is not eccentrically located due to the fact that the femaleconnectors 32 are located on diametrically opposed sides of the endfitting 20. The number of ports 30 provided on an end fitting 20 isdependent upon the requirement of the hydraulic system.

Annular grooves 45 are preferably formed on the exterior surface of theend fitting to receive anchoring devices as will be more fully describedwith reference to FIGS. 7 and 8 below.

Referring now to FIGS. 4 and 5, a prior art front end brake system ofFIG. 4 will be compared to a front end brake system made in accordancewith the present invention. Referring to FIG. 4, a master cylinder 50 isconnected to a chassis brake tube line 52 by a first wet fitting 42. Thechassis brake tube line is connected by a second wet fitting to a Tfitting 53. The T fitting 53 is then connected to two axle brake tubelines 54 by third and fourth wet fittings. The opposite ends of the axlebrake tube lines 54 are connected to brake hoses 21 by fifth and sixthwet fittings and the brake hoses 21 are in turn connected to the brakemechanism caliper 56, of the brake on the wheel by seventh and eighthwet fittings.

Referring now to FIG. 5, the brake system of the present invention isillustrated wherein a master cylinder 50 is connected by a first wetfitting to a chassis brake tube line 52 which is connected by a secondwet fitting at its other end to a manifold brake hose end fitting 20 ofa brake hose 21 which is connected by a third wet fitting on its otherend to the caliper 56 of the brake of one wheel. The manifold brake hoseend fitting 20 is connected by a fourth wet fitting to a second brakehose 21 through a male connector and a second female connector 32preferably formed through one of the wrench flats 41. The second brakehose 21 is connected by a fifth wet fitting on its other end to thebrake caliper 56 of the other wheel. The minimum number of wet fittingsrequired for the system shown in FIG. 6 is five while that of the priorart requires nine wet fittings.

As an alternative, an axle brake tube line 54 may be connected to themanifold brake hose end fitting 20 instead of the second brake hose 21if it is desirable to reduce the length of the second brake hose 21. Theopposite end of the axle brake tube line 54 would then be connected by asixth wet fitting to the second brake hose 21 adding one more wetfitting to the system.

FIGS. 6 and 7 depict rear axle assemblies 58 and their associated brakehose systems showing in FIG. 6 a prior art brake system and in FIG. 8 abrake system in accordance with the present invention.

Referring now to FIG. 6, the rear axle assembly 58 is shown with afragmentary portion of the frame 59 of a vehicle. The chassis brake tubeline 52 is secured to the frame 59 by means of a mounting flange 60which is secured to the frame and includes a bore 61 to which thechassis brake tube line 52 is connected at its fitting. THe chassisbrake tube line 52 is secured in the flange 60 by means of a clip 62 anda snap washer 63 which permit the brake lines to be disassembled fromthe vehicle for service and yet provide a secure mounting for the tubelines and brake hoses. A brake hose 21 is connected to the chassis braketube line 52 on one end and on its other end to a Y fitting 64, whichcould also be a T fitting 53 if desired. The Y fitting 64 is in turnconnected to two axle brake tube lines 54 which extend along the axletoward the right and left wheels and are secured to the axle by means ofmounting flanges 60 which are secured to the vehicle axle. The axlebrake tube lines 54 are connected to brake hoses 21 on their other endand secured in place by means of a clip 62 and snap washer 63 aspreviously described. The Y fitting 64 is secured to the axle by meansof a bolt 65 as is well known in the art. The brake hoses 21 extendbetween the axle brake tube lines 54 and the calipers 56 of each wheelbrake to accommodate movements of the caliper relative to the axle thatcould damage a less flexible tubing.

In the illustrated prior art rear brake system, a total of eight wetfittings are required between the master cylinder 50 and the brakecaliper 56 as follows: one between the chassis brake tube line 52 andthe brake hose having the Y fitting; two between the Y fitting 53 andthe axle brake tube lines 54; two between the other end of the axlebrake tube lines 54 and the two brake hoses 21; and, two between theother ends of the brake hoses 21 and the two calipers of the brakes oneach wheel. In addition, one wet fitting not shown on FIG. 7 is the wetfitting between the chassis brake tube line 52 and the master cylinder50.

Referring now to FIG. 7, a brake system made in accordance with thepresent invention is shown to include a chassis brake tube line 52 whichis connected to the master cylinder (not shown) and terminates in a maleconnector 37 and is connected to a manifold brake hose end fitting 20which is secured to a brake hose 21. The brake hose 21 on its oppositeend is connected directly to the caliper 56 of one wheel. The manifoldbrake hose end fitting 20 includes a side female connector 32 in one ofthe wrench flats 41. A chassis brake tube line 54 having a maleconnector 37 on both ends is connected on one end to the manifold brakehose end fitting 20 in the side receptacle 32. The opposite end of thechassis brake tube line 54 is connected to a brake hose 21 whichinterconnects the chassis brake tube line 54 to the caliper 56.

In the illustrated rear brake system of the present invention, a totalof six wet fittings are required between the master cylinder and thebrake calipers 56 as follows: one between the master cylinder and thechassis brake tube line 52, one between the male connector 37 on theopposite end of the chassis brake tube line 52 and the manifold brakehose end fitting 20; one between the manifold brake hose end fitting andchassis brake tube line 54, one between the other end of the chassisbrake tube line 54 and a brake hose 21 end fitting; and, two between thebrake hoses 21 and the brake calipers 56.

The precise configuration of the chassis brake tube lines, axle braketube lines and brake hose 21 routing will be dictated in part by therequirements of a particular vehicle. However, the manifold brake hoseend fitting 20 will also produce advantages results if it used as asymmetrical connector between two brake hoses of substantially equallength which are connected to a centrally disposed chassis brake tubeline.

New brake systems are presently being developed to prevent wheel lock-upby sensing devices which are conected in a feedback system whichmonitors wheel rotation. The anti-wheel lock-up system monitor wheelrotation at the wheel and include hydraulic, pneumatic, vacuum orelectronic systems which are preferably located adjacent the wheel.

Another development in braking systems is the provision of redundantbraking system that provide hydraulic pressure to each front disc brakecaliper via two separate pressure lines.

The above developments in brake systems can be easily accommodated by analternative split flow embodiment of the modular manifold brake hose endfittings of the present invention. Referring to FIG. 8, an unique splitflow embodiment of the present invention is shown wherein two parallelfluid circuit may be routed through the same manifold brake hose endfittings using the same connections to the chassis. The parallel fluidcircuit 67 is comprised of female connectors 32 interconnected by aconduit 68 which is separate from the internal conduit 28 of thehydraulic brake system. The parallel fluid circuit 67 may be apneumatic, vacuum or hydraulic system used in an anti-lock-up feedbacksystem or to provide a redundant braking system. If a redundant brakingsystem is desired, a sleeve 25 and tubular extension 26 for a crimpedfitting 23 may be provided which would be in fluid communication withthe conduit 68.

It will be readily appreciated that the manifold brake hose end fittingcan be modified to accommodate one, two, three or more separate flowpaths as needed. In all cases, at least one end of the modular manifoldbrake hose end fitting is assembled to a flexible reinforcedelastomeric, or rubber, hose of the brake system.

Thus, it is apparent that there has been provided, in accordance withthe invention, a manifold brake hose end fitting which may beincorporated in a system and used in a method that fully satisfies theobjects, aims and advantages set forth above. While the invention hasbeen described in conjunction with specific embodiments thereof, it isevident that many alternatives, modifications and variations will beapparent to those skilled in the art in light of the foregoingdescription. Accordingly, it is intended to embrace all suchalternatives, modifications and variations as fall within the spirit andscope of the appended claims.

I claim:
 1. A brake system comprising:a brake actuator for generating acontrol pressure; a master cylinder means for containing a hydraulicfluid and for generating an amplified output pressure in response tochanges in the control pressure, said master cylinder means beingoperatively connected to the brake actuator; a high pressure hydraulicfluid distribution system having a trunk line in fluid communicationwith the master cylinder for distributing hydraulic fluid to at leasttwo separate brake calipers; an end fitting at the opposite end of saidtrunk line from said master cylinder means including a male connectorcomprising a cylindrical threaded member having a concave conicalportion in the end face thereof; a first reinforced elastomeric brakehose having a manifold brake hose end fitting including first and secondfemale connectors being cylindrical openings having internally threadedcylindrical sides and end faces formed at the inner ends of saidcylindrical openings, said end faces having convex conical nipplescentrally located in said end faces, said nipples being in fluidcommunication with an internal conduit formed in said manifold brakehose end fitting for connecting the conduit to said trunk line endfitting through said first female connector, the brake hose beingdirectly connected to one of said brake calipers on its other end; and asecond brake hose having a male connector including a cylindricalthreaded portion having an end face including a concave conical nipplecentrally located therein at said end face, said second brake hose beingconnected to said second female connector on one end and being connectedto the other of said brake calipers on another end.
 2. The brake systemof claim 1 wherein said manifold brake hose end fitting is a solidone-piece body having an integral tubular cylindrical sleeve extendingfrom one end of the body, a tubular extension located concentricallywithin said sleeve, said brake hose being a reinforced elastomeric hosereceived between said sleeve and said extension and being retainedthereon by a crimped portion of said sleeve wherein said sleeve ismechanically deformed radially inwardly at an intermediate pointthereon.
 3. The brake system of claim 1 further comprising:a secondfluid distribution system for distribution a fluid to an apparatusadjacent a wheel of a vehicle; third and fourth female connectors beingcylindrical openings having internally threaded cylindrical sides andend faces formed at the inner ends of said cylindrical openings, saidend faces having convex conical nipples centrally located in said endfaces, said third and fourth female connectors being interconnectedthrough said manifold end fitting, said secondary fluid distributionsystem being routed through the third and fourth receptacles, whereby asingle manifold end fitting is included in the hydraulic fluid systemand a secondary fluid distribution system.
 4. A method of assemblinghigh pressure brake fluid distribution conduits on a vehicle comprisingthe steps of:attaching a trunk line having first and second ends, saidfirst end being connected to a master cylinder, said second end havingan end fitting having a male connector including a cylindrical threadedportion; securing said second end to the vehicle at a site on thevehicle not movable relative to the vehicle; threadably attaching afirst brake hose to said male connector, said first brake hose includinga reinforced elastomeric hose attached on one end to a manifold endfitting and on another end to an end fitting having a male connectorincluding a cylindrical threaded portion, said manifold end fittinghaving at least two female connectors formed therein, said femaleconnectors including a threaded cylindrical bore, wherein one of saidfemale connectors is threaded onto said male connector on the second endof the trunk line; threadably attaching a second brake hose to thesecond female connector of the manifold end fitting, said second brakehose including a reinforced elastomeric hose attached on both ends toend fittings, each end fitting have a male connector including acylindrical threaded portion which is received in said second femaleconnector; threadably attaching the male connector formed at the otherend of said first brake hose to a first brake caliper; and attaching themale connector located at the other end of said brake hose to a secondbrake caliper.
 5. The method of claim 4 wherein said trunk line is asubstantially rigid tubular fluid conduit and said second brake hose isa substantially rigid tubular fluid conduit which is serially connectedto a flexible brake hose and said method further comprises securing therigid tubular fluid conduit to an axle of the vehicle.
 6. The method ofclaim 4 including the additional steps of:attaching a first end fittingof a second fluid conduit not in fluid communication with said trunkline by a male connector including a cylindrical threaded portion to athird female connector formed in said manifold end fitting, said femaleconnector including a threaded cylindrical bore; threadably attaching asecond end fitting of said second fluid conduit to a fourth femaleconnector formed in said manifold end fitting, said male connector ofthe second end fitting including a cylindrical threaded portion and saidfemale connector includes a threaded cylindrical bore; said third andfourth female connectors being in fluid flow connection through themanifold end fitting whereby said method of installing brake fluidconduits on a vehicle also includes installing a separate fluid conduitin the same manifold end fitting used by the brake fluid conduit.